/*******************************************************************************
 * Copyright (c) 2009-2011 Luaj.org. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/
package org.mini2Dx.miniscript.gradle.compiler;

import org.luaj.vm2.Globals;
import org.luaj.vm2.LuaFunction;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Prototype;
import org.luaj.vm2.luajc.JavaGen;
import org.luaj.vm2.luajc.JavaLoader;

import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.Hashtable;

/**
 * Patched version to LuaJC to fix package declarations
 */
public class PatchedLuaJC implements Globals.Loader {

	public static final PatchedLuaJC instance = new PatchedLuaJC();

	/**
	 * Install the compiler as the main Globals.Loader to use in a set of globals.
	 * Will fall back to the LuaC prototype compiler.
	 */
	public static final void install(Globals G) {
		G.loader = instance;
	}

	protected PatchedLuaJC() {}

	public Hashtable compileAll(InputStream script, String chunkname, String filename, Globals globals, boolean genmain) throws IOException {
		final String classname = toStandardJavaClassName( chunkname );
		final Prototype p = globals.loadPrototype(script, classname, "bt");
		return compileProtoAndSubProtos(p, classname, filename, genmain);
	}

	public Hashtable compileAll(Reader script, String chunkname, String filename, Globals globals, boolean genmain) throws IOException {
		final String classname = toStandardJavaClassName( chunkname );
		final Prototype p = globals.compilePrototype(script, classname);
		return compileProtoAndSubProtos(p, classname, filename, genmain);
	}

	private Hashtable compileProtoAndSubProtos(Prototype p, String classname, String filename, boolean genmain) throws IOException {
		final String luaname = toStandardLuaFileName( filename );
		final Hashtable h = new Hashtable();
		final JavaGen gen = new JavaGen(p, classname, luaname, genmain);
		insert( h, gen );
		return h;
	}

	private void insert(Hashtable h, JavaGen gen) {
		h.put(gen.classname, gen.bytecode);
		for ( int i=0, n=gen.inners!=null? gen.inners.length: 0; i<n; i++ )
			insert(h, gen.inners[i]);
	}

	public LuaFunction load(Prototype p, String name, LuaValue globals) throws IOException {
		String luaname = toStandardLuaFileName( name );
		String classname = toStandardJavaClassName( luaname );
		JavaLoader loader = new JavaLoader();
		return loader.load(p, classname, luaname, globals);
	}

	public static String toStandardJavaClassName( String luachunkname ) {
		String stub = toStub( luachunkname );
		StringBuffer classname = new StringBuffer();
		for (int i = 0, n = stub.length(); i < n; ++i) {
			final char c = stub.charAt(i);
			switch(i) {
			case 0:
				if(Character.isJavaIdentifierStart(c)) {
					classname.append(c);
				} else {
					classname.append('_');
				}
				break;
			default:
				if(c == '/') {
					classname.append(c);
				} else if(Character.isJavaIdentifierPart(c)) {
					final char previousChar = stub.charAt(i - 1);
					if(previousChar == '/') {
						if(!Character.isJavaIdentifierStart(c)) {
							classname.append('_');
							classname.append(c);
						} else {
							classname.append(c);
						}
					} else {
						classname.append(c);
					}
				} else {
					classname.append('_');
				}
				break;
			}
		}
		return classname.toString();
	}

	private static String toStandardLuaFileName( String luachunkname ) {
		String stub = toStub( luachunkname );
		String filename = stub.replace('.','/')+".lua";
		return filename.startsWith("@")? filename.substring(1): filename;
	}

	private static String toStub( String s ) {
		String stub = s.endsWith(".lua")? s.substring(0,s.length()-4): s;
		return stub;
	}
}
